S235JR is a non-alloy structural steel grade with a minimum yield strength of 235 MPa, designed for general construction use. It is impact-tested at +20°C (room temperature) to ensure a minimum toughness of 27 Joules, making it suitable for applications in moderate climates or indoor environments where low-temperature brittleness is not a concern.
S235J0 is a similar non-alloy structural steel with the same minimum yield strength of 235 MPa but is impact-tested at 0°C. This ensures reliable toughness in colder conditions, making it a preferred choice for outdoor structures, bridges, or any application exposed to near-freezing or temperate climates, providing an extra safety margin against brittle fracture.
The core difference between S235JR and S235J0 is their guaranteed impact toughness at different temperatures. Both are non-alloy structural steels with the same minimum yield strength (235 MPa), but the suffix indicates their testing conditions for resistance to brittle fracture.
Here is a direct comparison:
| Feature | S235JR | S235J0 |
|---|---|---|
| Key Difference | Impact test at a higher temperature | Impact test at a lower temperature |
| Test Temperature | +20°C (Room Temperature) | 0°C |
| Minimum Impact Energy | 27 Joules | 27 Joules |
| Typical Use Case | General structures in moderate/warm climates (indoor or ambient temperatures). | Structures exposed to colder climates, where temperatures can approach or reach freezing. |
| Safety Implication | Suitable for environments where the material temperature won't drop near freezing in service. | Provides a safety margin against brittle fracture for applications experiencing chillier conditions. |
Why This Matters:
Steel can become more brittle as temperatures drop. The "J0" grade is certified to maintain its toughness at 0°C, making it a safer and more reliable choice for:
Outdoor structures in temperate or cold regions (e.g., bridges, pylons, balconies).
Any application where the steel's service temperature may fall to freezing or below.
In summary:
If your project is for a consistently warm environment or an indoor application, S235JR is typically sufficient. If the structure will be exposed to colder temperatures, S235J0 (or an even more resilient grade like S235J2 for -20°C) should be specified to ensure structural integrity and safety. The choice is often dictated by construction codes and the project's geographical location.
What is S235JR?
S235JR is a non-alloy structural steel grade according to the European standard EN 10025-2, known for its minimum yield strength of 235 MPa.
What is the chemical composition of S235JR steel?
Its typical composition includes max 0.17% Carbon, max 1.40% Manganese, and controlled levels of phosphorus and sulfur.
What is the yield strength of S235JR?
The minimum yield strength of S235JR steel is 235 Megapascals (MPa).
What is the difference between S235JR and S235J0?
The main difference is in impact toughness at lower temperatures; S235JR is tested at +20°C, while S235J0 is tested at 0°C.
Is S235JR equivalent to A36?
S235JR is a similar general-purpose structural steel to ASTM A36, but they are from different standards and have minor differences in properties.
What is the density of S235JR steel?
The density of S235JR is approximately 7.85 grams per cubic centimeter (g/cm³), the same as most carbon steels.
Can S235JR be welded?
Yes, S235JR has good weldability using common methods like SMAW, MIG, and MAG without requiring pre-heating under normal conditions.
What is S235JR used for?
It is commonly used in general construction, steel frames, machinery components, and various structural applications.
What does the 'JR' mean in S235JR?
The 'JR' indicates the Charpy V-notch impact energy requirement at room temperature (+20°C), which is 27 Joules minimum.
Is S235JR corrosion resistant?
No, S235JR is not a corrosion-resistant grade. It is a non-alloy carbon steel and requires protective coatings like paint or galvanization for outdoor use.
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff.
